The name of the crush bucket used for the first step of
the CRUSH rule. For intance step take default.

Type:

String

Required:

No.

Default:

default

crush-failure-domain={bucket-type}

Description:

Ensure that no two chunks are in a bucket with the same
failure domain. For instance, if the failure domain is
host no two chunks will be stored on the same
host. It is used to create a CRUSH rule step such as step
chooseleaf host.

Type:

String

Required:

No.

Default:

host

crush-device-class={device-class}

Description:

Restrict placement to devices of a specific class (e.g.,
ssd or hdd), using the crush device class names
in the CRUSH map.